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Prevention of Renal Failure by Nitric Oxide in Prolonged Cardiopulmonary Bypass.

Phase 1
Completed
Conditions
Cardiac Valve Replacement Complication
Heart Valve Diseases
Heart; Complications, Valve, Prosthesis
Interventions
Other: inhaled Nitrogen
Other: inhaled nitric oxide
Registration Number
NCT01802619
Lead Sponsor
Xijing Hospital
Brief Summary

Prolonged periods of cardiopulmonary bypass (CPB) cause high levels of plasma free haemoglobin(Hb) and are associated with increased morbidity. We hypothesized that repletion of nitric oxide (NO) during and after the surgical procedure on CPB may protect against endothelium dysfunction and organ failure caused by plasma-Hb induced NO scavenging.

Detailed Description

Prolonged periods of cardiopulmonary bypass (CPB) cause high levels of plasma free haemoglobin(Hb) and are associated with increased morbidity. We hypothesized that repletion of nitric oxide (NO) during and after the surgical procedure on CPB may protect against endothelium dysfunction and organ failure caused by plasma-Hb induced NO scavenging. There are three possible beneficial mechanisms of delivering NO:

1. Nitric oxide reduces ischemia-reperfusion injury (such as in acute myocardial infarction, stroke, and acute tubular necrosis).

2. Nitric oxide has anti-inflammatory properties. As antioxidants, exogenous NO may reduce injury by counteracting the cytotoxic effects of reactive oxygen species, modulating leukocyte recruitment, edema formation and tissue disruption.

3. Exogenous nitric oxide prevents noxious effects of hemolysis-associated NO dysregulation. During hemolysis, nitric oxide gas oxidized of plasma oxyhemoglobin to methemoglobin, thereby inhibiting endogenous endothelium NO scavenging by cell-free Hb.

NO depletion during hemolysis and its sequelae. The release of plasma free Hb (with Fe2+ iron) by hemolysis avidly scavenges nitric oxide (NO) by the dioxygenation reaction. Elevated plasma ferrous Hb levels can induce a "NO deficiency" state. Reduced vascular nitric oxide levels can contribute to vasoconstriction, inflammation, and thrombosis, potentially contributing to systemic endothelial dysfunction after cardiac surgery with CPB.

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
217
Inclusion Criteria
  • Provide written informed consent
  • Are > 18 years of age
  • Elective cardiac or aortic surgery with CPB, when the surgeon plans double valve replacement.
  • Stable pre-operative renal function, without dialysis.
Exclusion Criteria
  • Emergent cardiac surgery
  • Life expectancy < 1 year
  • Hemodynamic instability as defined by a systolic blood pressure <90 mmHg
  • Administration of ≥1 Packed Red Blood Cell transfusion in the week before surgery
  • X-ray contrast infusion less than 1 week before surgery
  • Anticipate administration of nephrotoxic agents, such as hydroxyethyl starch
  • Evidence of intravascular or extravascular hemolysis

Study & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Arm && Interventions
GroupInterventionDescription
inhaled nitrogeninhaled NitrogenUsing an Inovent (Ikaria Inc, N.J., USA) or volumetrically-calibrated flowmeters, pure nitrogen (placebo) is mixed with pure O2 or air. During CPB the gas mixture is delivered through the extracorporeal oxygenator, after CPB the NO is delivered through the inspiratory limb of the anesthetic or ventilator circuit.
inhaled nitric oxideinhaled nitric oxideUsing an Inovent (Ikaria Inc, N.J., USA) or volumetrically-calibrated flowmeters, 800 ppm NO gas is mixed with pure O2 or air to obtain a final concentration of 80 ppm NO. During CPB the gas mixture is delivered through the extracorporeal oxygenator, after CPB the gas is delivered through the inspiratory limb of the anesthetic or ventilator circuit. NO, NO2 and O2 and methemoglobin levels are monitored by an unblinded observer.
Primary Outcome Measures
NameTimeMethod
acute kidney injuryan increase of serum creatinine by 50% within 7 days after surgery, or an increase of serum creatinine by 0.3 mg/dl within 2 days after surgery

acute kidney injury was defined by the KDIGO criteria

Secondary Outcome Measures
NameTimeMethod
Chronic kidney diseaseat 30 days, 90 days, and 1 year following ICU admission

defined as eGFR\<60 mL/min/1.73m2

Incidence of nonfatal stroke and nonfatal myocardial infarction.at 30 days, 90 days, and 1 year following ICU admission

Nonfatal stroke will be assessed by the NIH Stroke Scale at baseline before surgery and at 28 days, 60 days, 90 days and 1 year after surgery.

Nonfatal myocardial infarction is defined by the third universal definition of MI released in 2012 by the ESC/ACCF/AHA/WHF.

Major adverse kidney events (MAKE)at 30 days, 90 days, and 1 year following ICU admission

a composite outcome of loss of 25% of eGFR from baseline, end stage renal disease requiring a continuous renal replacement therapy and mortality.

Renal Replacement Therapyat 30 days, 90 days, and 1 year following ICU admission

the incidence of need for Renal Replacement Therapy

Loss of 25% of eGFR compared to baselineat 30 days, 90 days, and 1 year following ICU admission

Loss of 25% of eGFR compared to baseline

Quality of lifeat 30 days, 90 days, and 1 year following ICU admission

The quality of life will be evaluated by the Katz Index of In dependence in Activities of Daily living

overall mortalityat 30 days, 90 days, and 1 year following ICU admission

all cause mortality

Trial Locations

Locations (1)

Xijing Hospital

🇨🇳

Xi'an, Shaanxi, China

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